# Data Model — 093 SCOPE-001 Workspace ID Isolation

## Core Entities

### Workspace
- `workspaces`:
  - `id` (bigint)
  - `name`, `slug`, timestamps

### Tenant
- `tenants`:
  - `id` (bigint)
  - `workspace_id` (bigint, intended non-null logically; currently nullable in schema)

**Ownership rule**: A tenant belongs to exactly one workspace; this mapping is the source of truth for deriving workspace bindings.

## Tenant-owned Tables (must become workspace-bound)

For each table below:
- Add `workspace_id` (bigint FK to `workspaces.id`)
- Enforce `workspace_id` derived from tenant (DB-level composite FK on Postgres/MySQL)
- Keep `tenant_id` immutable (application enforcement)

### policies
- Existing: `tenant_id`, `external_id`, `policy_type`, etc.
- Add: `workspace_id`

### policy_versions
- Existing: `tenant_id`, `policy_id`, `snapshot`, etc.
- Add: `workspace_id`

### backup_sets
- Existing: `tenant_id`, status/count, etc.
- Add: `workspace_id`

### backup_items
- Existing: `tenant_id`, `backup_set_id`, `payload`, etc.
- Add: `workspace_id`

### restore_runs
- Existing: `tenant_id`, `backup_set_id`, status, preview/results, etc.
- Add: `workspace_id`

### backup_schedules
- Existing: `tenant_id`, enabled/frequency/schedule fields
- Add: `workspace_id`

### inventory_items
- Existing: `tenant_id`, policy identifiers, `meta_jsonb`, last_seen fields
- Add: `workspace_id`

### inventory_links
- Existing: `tenant_id`, source/target relationship identifiers
- Add: `workspace_id`

### entra_groups
- Existing: `tenant_id`, entra_id, display fields
- Add: `workspace_id`

### findings
- Existing: `tenant_id`, fingerprint, status/severity, run references
- Add: `workspace_id`

### entra_role_definitions
- Existing: `tenant_id`, entra_id, display fields
- Add: `workspace_id`

### tenant_permissions
- Existing: `tenant_id`, permission_key, status
- Add: `workspace_id`

## Audit Logs (scope invariants)

### audit_logs
- Existing: `tenant_id` nullable, `workspace_id` nullable, action/resource fields

**Invariant**:
- Tenant-scoped audit entry: `tenant_id != null` implies `workspace_id != null`.
- Workspace-only audit entry: `workspace_id != null` and `tenant_id == null` is allowed.
- Platform-only audit entry: both null is allowed.

## Relationship + Constraint Strategy

### Tenant-owned enforcement (Postgres/MySQL)
- Composite FK on each tenant-owned table:
  - `(tenant_id, workspace_id) → tenants(id, workspace_id)`
- Standard FK on `workspace_id → workspaces.id`

### SQLite
- Foreign key / composite constraint enforcement is limited.
- Testing relies on application enforcement + basic NOT NULL where feasible.